Changes

[[File:4 week embryo brain.jpg|thumb|150px|left|Embryonic Brain Development]]

[[File:4 week embryo brain.jpg|thumb|150px|left|Embryonic Brain Development]]

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After these initial expansions, a series of further developments occurs to form some of the major landmarks in the brain. The mesencephalon narrows prior to the proencephalon resulting in the formation of the 'Foramen of Munro' and the 'Cerebral Aqueduct'. The proencephalon develops two further pouches in the cranial lateral aspect which are the foundations of the 'Lateral Ventricles' and the 'Third Ventricle'.

After these initial expansions, a series of further developments occurs to form some of the major landmarks in the brain. The mesencephalon narrows prior to the proencephalon resulting in the formation of the 'Foramen of Munro' and the 'Cerebral Aqueduct'. The proencephalon develops two further pouches in the cranial lateral aspect which are the foundations of the 'Lateral Ventricles' and the 'Third Ventricle'. The rhombencephalon expansion forms the 'Fourth Ventricle' and the 'Central Canal'.

The development of the brain continues with the forebrain out-pouchings developing into hemispheres and growing dorsolaterally, forming the telencephalon. These hemispheres grow over the newewly formed diencephalon, mesencephalon and back to the metencephalon. During this stage other developmental landmarks are developed including the Cepahlic flexure, Pontine flexure, Cervical flexure and the myelencephalon. An out-pouching for the cerebellum is also present at this stage of development, together with a choroid plexus (for the production of CSF) and defined lateral ventricles.

===Caudal Spinal Cord Development===

===Caudal Spinal Cord Development===